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 KAC URX and URX II - 10.75?
LeonC  [Team Member]
7/2/2012 3:38:22 AM EST
Can someone please explain the differences between the URX and URX II - both 10.75" rails.

Also, what kind of gas-block would clear the rails without having to get shaved down?
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KevinB  [Industry Partner]
7/2/2012 11:21:52 AM EST
URX did not have the integrated front sights –– and used the older castle nut style barrel nut.
Very very few of those where sold commercially.


As so what gas block - that depends on what gas port position you are using on the barrel.
cms81586  [Team Member]
7/2/2012 12:11:16 PM EST
Originally Posted By LeonC:
Can someone please explain the differences between the URX and URX II - both 10.75" rails.

Also, what kind of gas-block would clear the rails without having to get shaved down?


With the URXII mid length (10.75") you typically need a carbine length gas system or shorter. With the rifle length URX II you typically need a mid length gas system or shorter. With the URX III I believe you can run any length gas system since there is no built in front BUIS getting in the way and the rail has enough internal clearance for just about any low profile gas block (I've used Noveske and it fits well).

CMS
LeonC  [Team Member]
7/2/2012 4:02:23 PM EST
Originally Posted By KevinB:
URX did not have the integrated front sights –– and used the older castle nut style barrel nut.
Very very few of those where sold commercially.


As so what gas block - that depends on what gas port position you are using on the barrel.


Thank you!

Oddly enough Aimsurplus confused me.
Looks like a URX II ...

http://www.aimsurplus.com/product.aspx?item=XKA205493&name=Knights+Armament+10.75%22+URX+RAS+Railed+Hanguard&groupid=301&search=URX

Also would any low-profile gas block work with the URX II?
bupton  [Team Member]
7/4/2012 1:35:38 PM EST
Originally Posted By cms81586:
Originally Posted By LeonC:
Can someone please explain the differences between the URX and URX II - both 10.75" rails.

Also, what kind of gas-block would clear the rails without having to get shaved down?


With the URXII mid length (10.75") you typically need a carbine length gas system or shorter. With the rifle length URX II you typically need a mid length gas system or shorter. With the URX III I believe you can run any length gas system since there is no built in front BUIS getting in the way and the rail has enough internal clearance for just about any low profile gas block (I've used Noveske and it fits well).

CMS

The URXIII does still use the integrated flip up front sight, it's the 3.1 that does not use the integrated sight. Also, the mid-length URXII system spec'd on the SR-15 utilizes a mid-length gas system, and has the gas block mounted just outside of the rail.
LeonC  [Team Member]
7/5/2012 3:45:27 AM EST
What about gas blocks?
Which would I need the .650 or .750?

Is there any clearance issue?
They don't need to be shaved down further?
I will be using a carbine gas tube.
KevinB  [Industry Partner]
7/5/2012 4:23:22 AM EST
Gas Block will depend on your barrel.

Using a Midlength/Medium URX with a carbine gas system - most of the low profile gas blocks will fit.

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